A mathematically rigorous assessment of the efficiency of quarantining and contact tracing in curbing the COVID-19 epidemic

  title={A mathematically rigorous assessment of the efficiency of quarantining and contact tracing in curbing the COVID-19 epidemic},
  author={Amaury Lambert},
In our model of the COVID-19 epidemic, infected individuals can be of four types, according whether they are asymptomatic (A) or symptomatic (I), and use a contact tracing mobile phone app (Y) or not (N). We denote by f the fraction of A’s, by y the fraction of Y’s and by R0 the average number of secondary infections from a random infected individual.We investigate the effect of non-electronic interventions (voluntary isolation upon symptom onset, quarantining private contacts) and of… 

Figures from this paper

Increasing efficacy of contact-tracing applications by user referrals and stricter quarantining
Using CTAs with mild quarantine measures is effective in reducing the maximum hospital load and the number of people who become ill, but leads to a relatively high quarantine load, which may cause economic disruption.
Control Of Epidemic Spreads Via Testing And Lock-Down
Testing and lock-down are interventions that can combat the spread of an infectious disease. Testing is a targeted instrument that permits the isolation of infectious individuals. Lock-down, on the
Effectiveness modelling of digital contact-tracing solutions for tackling the COVID-19 pandemic
A wide range of factors is reviewed and classifies them into three categories of technical, epidemiological and social ones, and incorporates these into a compact mathematical model that evaluates the effectiveness of digital contact-tracing apps based on received signal strength measurements.
Evaluating the Effectiveness of COVID-19 Bluetooth-Based Smartphone Contact Tracing Applications
The results show that smartphone contact tracing can only be effective when combined with other mild measures that can slightly reduce the reproductive number R0 (for example, social distancing), and that a centralized model is much more effective, requiring an application utilization percentage of about 50% to control an outbreak.
The epidemiological impact of the NHS COVID-19 App.
The impact of the NHS COVID-19 app for England and Wales, from its launch on 24 September 2020 through to the end of December 2020, is investigated to provide evidence for continued development and deployment of such apps in populations that are awaiting full protection from vaccines.
Probabilistic and mean-field model of COVID-19 epidemics with user mobility and contact tracing
A detailed discrete-time model of COVID-19 epidemics coming in two flavours, mean-field and probabilistic is proposed, and its application as well as underlying estimation procedures are discussed.
Contact Tracing by Giant Data Collectors: Opening Pandora’s Box of Threats to Privacy, Sovereignty and National Security
A number of very problematic aspects and threats that the GAEN approach creates through its security and privacy weaknesses but also through the threats that it poses on technological sovereignty and the public are pointed out.
Epidemiological and public health requirements for COVID-19 contact tracing apps and their evaluation
Digital contact tracing should be integrated with local health policy, provide rapid and accurate notifications to exposed individuals, and encourage high app uptake and adherence to quarantine.


The Effectiveness of Contact Tracing in Emerging Epidemics
There is no general predictive formula for the proportion to be traced and variability in time to detection is favourable for effective tracing, so tracing effectiveness need not be sensitive to the duration of the latent period and tracing delays.
Feasibility of controlling COVID-19 outbreaks by isolation of cases and contacts
Factors that make an infectious disease outbreak controllable.
It is concluded that severe acute respiratory syndrome and smallpox are easier to control using these simple public health measures and should be a priority during an outbreak of a novel infectious agent.
Feasibility of controlling 2019-nCoV outbreaks by isolation of cases and contacts
It is found that in most scenarios contact tracing and case isolation alone is unlikely to control a new outbreak of 2019-nCov within three months, and the probability of control decreases with longer delays from symptom onset to isolation, fewer cases ascertained by contact tracing, and increasing transmission before symptoms.
Estimating the burden of SARS-CoV-2 in France
France has been heavily affected by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and went into lockdown on 17 March 2020, and population immunity appears to be insufficient to avoid a second wave if all control measures are released at the end of the lockdown.
Epidemiology and Transmission of COVID-19 in Shenzhen China: Analysis of 391 cases and 1,286 of their close contacts
This work shows that heightened surveillance and isolation, particularly contact tracing, reduces the time cases are infectious in the community, thereby reducing R.CoV-2's overall impact, however, its overall impact is uncertain and highly dependent on the number of asymptomatic cases.
A high-resolution human contact network for infectious disease transmission
High-resolution data of CPIs during a typical day at an American high school is obtained, permitting the reconstruction of the social network relevant for infectious disease transmission and suggested that contact network data are required to design strategies that are significantly more effective than random immunization.
Suppression of COVID-19 outbreak in the municipality of Vo, Italy
New light is shed on the frequency of asymptomatic SARS-CoV-2 infection and their infectivity (as measured by the viral load) and new insights are provided into its transmission dynamics, the duration of viral load detectability and the efficacy of the implemented control measures.
Comparing nonpharmaceutical interventions for containing emerging epidemics
It is shown that the comparative effectiveness of symptom monitoring and quarantine depends critically on the natural history of the infectious disease, its inherent transmissibility, and the intervention feasibility in the particular healthcare setting, and this quantitative framework can guide policymakers on how best to use nonpharmaceutical interventions and prioritize research during an outbreak of an emerging pathogen.
Epidemiological parameters of coronavirus disease 2019: a pooled analysis of publicly reported individual data of 1155 cases from seven countries
Background The outbreak of coronavirus disease 2019 (COVID-19) has been declared a pandemic by the World Health Organization, while several key epidemiological parameters of the disease remain to be